In 2012 the UK Government’s Department for Environment, Food & Rural Affairs and Environment Agency (DEFRA) produced a Climate Change Risk Assessment (CCRA) evaluating the main climate-related risks and opportunities in eleven sectors in the UK, over the course of the current century to 2100.
The intention was that it will be used to identify priority areas for action and develop a national adaptation programme. This article summarises the main environmental and social consequences of climate change and the impact of key socio-economic factors as identified in the CCRA sector report on Biodiversity and Ecosystems Services. This sector in particular was chosen for in-depth analysis since biodiversity is essential to human survival and well-being, through food production and energy security, as well as financial and social factors such as leisure, tourism, education, and cultural value placed on nature.
Environmental consequences of climate change
The CCRA identified thirteen major environmental risks resulting from the impact of climate change on biodiversity. The report outlines the current risk status, the potential impact of climate change on each risk factor, the implications for the ecosystem services sector, and the implications for adaptation. Here we outline the salient elements of each risk.
It should be noted that the CCRA considers the risks of a changing climate in the UK only, not the risks to which the UK may be exposed from global climate-related events. There is likely to be an impact on the UK economy from climate-related disruption elsewhere in the world, for example, through international trade, supply chains, and migration. As yet, there is little research on the likelihood and potential impact of such events.
Changes in soil moisture levels
- Most habitats and species in the UK are adapted to a rather wet environment. Climate change forecasts expect moisture levels to decrease, so habitats that are sensitive to moisture levels will suffer if the climate becomes much drier. Reduction in function of loss of habitats could impact food production, water supply and quality, and use of land for tourism and leisure. Reduced soil moisture is also linked to increased risk of wildfires, and the vulnerability of species to pests and disease. Potential adaptations to this risk are highly species and site specific, such as developing new woodland areas and managing bog land, with no universal solution.
Extreme flooding and coastline changes
- A coastal environment is dynamic and with high biodiversity, supporting a wide range of species. Changes in sea level can change coastal habitats through erosion or sediment deposits, providing both risks and new opportunities to plant and animal species. Some coastal features also play an important role in protecting human settlements from flooding. Typically coastal changes occur over a long period of time but events such as storm surges and major flooding can lead to large-scale changes in a short period of time (although this is rare). Climate change is expected to lead to sea level rise and both loss of habitats and creation of new ones around the whole of the UK, with South West and East England worst affected. All studies project significant losses of coastal habitats, but since coastal land often provides leisure, landscape and tourism benefits, adapting and managing new coastal habitats could be cost-effective.
Increased risk from pests, disease and invasive non-native species
- These issues are interlinked and the risk is expected to increase due to climate change because many species are climate sensitive, and also because generally warmer winters provide a more conducive environment for nonnative species and pathogens. Most of the research to date has focussed on human health effects, but the risk also applies to broader biodiversity. There is already legislation to prevent the introduction of non-native species (either deliberate or accidental), which may displace existing species and lead to the introduction of new pests and diseases as well as disrupt agriculture. However, many have already been introduced in the UK and it is possible that a changing climate may favour non-native species to the detriment of native ones.
Species unable to track changing climate space
- Species distribution is often associated with a particular range of climate parameters, so changing climate is likely to shift their preferred habitat either geographically or in terms of size. Some species may not be able to find an available and suitable new habitat, leaving them vulnerable to extinction. In turn this reduces biodiversity and potentially the resilience of the local ecosystem. Human management of local ecosystems may be possible but the outcome is uncertain.
Impact of climate mitigation programmes
- This consequence is indirectly related to climate change, resulting from lead to a change in rainfall patterns, and indirectly impact the use of fertilisers in agriculture. The key challenge is to reduce pollution at its source.
Changes in soil organic carbon
- The organic content of soil influences the supply of nutrients and water to plants and the release of greenhouse gases. All components of soil are considered to be at risk from climate change, reducing the ability of the ecosystem to function. Land use change has been the biggest driver of changes in soil organic carbon in the UK and soil erosion is also a problem. While climate change may lead to increased atmospheric carbon dioxide which could potentially increase plant productivity, temperature increases are likely to increase biomass decomposition (reducing soil organic carbon) and the combination of drier summers and wetter winters to increase soil erosion. Adaptation responses should focus on protecting active peatlands that sequester large amounts of carbon.
Changes in species migration pattterns
- Many animals, especially birds, migrate to warmer climates in winter. Changing climates can therefore impact migration patterns. This may present both risks and opportunities to migratory species. Observations suggest that patterns are already changing, in terms of geography and timing, behaviour which itself might be considered an adaptation to climate change. However concern is that it may impact breeding patterns and successes.
Increased water temperature
- Aquatic species are generally highly sensitive to water temperatures, and the stratification of water bodies can also be impacted by climate chance, affecting the supply of oxygen and nutrients which in turn affects fish growth and viability. Adaptation possibilities include direct management of the local ecosystem through release of cooler water into stream and rivers, planting tree shade, and modifying stream topography, through there is limited evidence on whether this is likely to be effective.
Impacts on water quality
- Water pollution is a major source of damage to aquatic habitats. It can occur through human and agricultural waste deliberately or accidentally deposited in water bodies, and can be exacerbated by low rainfall. Climate change may lead to a change in rainfall patterns, and indirectly impact the use of fertilisers in agriculture. The key challenge is to reduce pollution at its source.
Generalist species benefiting at the expense of specialists
- Changing environments will benefit species that have less specific habitat requirements, possibly leading to an overall reduction in biodiversity. The magnitude of the effect from climate change will depend on the rate of change, since a rapid change makes it more difficult for a specialist species to adapt.
Increased risk of wildfires
- Hotter, drier summers, and reduced soil moisture as described above, lead to greater fire risk. This can result in habitat destruction and species extinction, as well as increased soil erosion and water pollution. In practice most wildfires are started by people, either deliberately or accidentally, hence active management of access and leisure is critical to adaptation.
Reduced water quantity
- A reduction in water supply due to climate change combined with an increase in demand for agricultural irrigation will have an impact on the ability of aquatic ecosystems to maintain and replenish. It is known that low water flows can lad to increases in pollution and nutrient concentrations. This can affect both wildlife and drinking water. The potential drying-up of watercourses also has implications for wider landscape amenity.
While the impact of climate change on some species is already well understood, less is known about the interactions of different species and of habitat change. The inevitable impact of climate change on most ecosystems is exacerbated by human-driven factors such as land use change and pollution. Some ecosystems may prove resilient to some climate change impacts, but the evidence suggests that most need to be supported by a planned adaptation response if irreversible changes to ecosystems are to be prevented.
Many of these issues described above are not unique to biodiversity and ecosystems services. Those that are particularly interdependent with other sectors include floods and coastal erosion, water quality and availability, land use change, pollution and invasive species. In addition the CCRA outlines several social consequences:
- Many diseases affecting people are also found in animal and plant habitats. A rise in pests and disease may have an impact on human health.
- Much of the UK’s natural environment and landscape is a great cultural and tourism asset; protecting it will have benefits for cultural wellbeing and the economy.
Governance and regulation
- Many ecosystems are already partly managed and will need human intervention to adapt to a changing climate, organised on a sufficiently broad scale.
- The ability to adapt will depend on public perception and willingness; including changes in the way we view the value of natural assets and non-market goods in economic assessments.
Socio-economic factors contributing to climate change risks
Six key socio-economic drivers were identified within the CCRA and their impact on biodiversity considered:
- Changes in the size and distribution of populations and related social pressure in the form of, for example, housing and education. This is believed to impact all biodiversity risks such as soil changes, species behaviour, water quality, and in particular increased risk from pests and diseases.
- Events such as war, natural disasters and economic crises can affect global stability, with less stability associated with a high degree of pressure on governments. Its impact on biodiversity is less significant than some of the other socio-economic factors, and seen mainly in increased risk from pests and diseases through international trade, climate mitigation programmes, and changes in species’ migration patterns through local conditions at the breeding or winter sites or along migration routes.
Distribution of wealth
- Distribution of wealth affects and can be affected by changes in coastal land use as a result of sea level rises, since coastal land provides a number of ecosystem services such as tourism, recreation and food production. Climate mitigation programmes can also be influenced and in sensitive areas there is increased risk of wildfire with increases human leisure use, and an impact on water availability as demand goes up.
- The direction of change in consumer values towards either wealth generation and material goods, or towards leisure and a focus on non-market goods and services such as conservation, affects many areas of biodiversity especially an increased risk from pests and disease through greater global trade in increasingly “exotic” goods.
Local versus national government decision-making
- Local versus national government decision-making is likely to impact all biodiversity risks but in particular climate mitigation measures, which are strongly influenced by public perception, such as developing an energy strategy and use of renewable energy,
Urbanisation versus rural development strongly affects many areas of biodiversity including species behaviour and soil changes through land use change, and water quality and availability through increasing demand for irrigation water versus water for consumption.
Human well-being is inextricably linked with the environment, in often complex way. Some human populations are particularly vulnerable to the effects of natural hazards, changes to the clean water supply, or disruption to primary industries such as agriculture through climate change. In addition, the cultural benefits of the environment, such leisure and well-being, can also be lost through changes to the environment.